This study evaluates the efficacy of supplemental pancreatic enzymes in patients with chronic diarrhea related to HIV. Most of these patients, however, have diarrhea related to anti-retroviral therapy. Studies suggest these enzymes are helpful. We are performing a randomized double-blind placebo-controlled crossover trial to evaluate the efficacy of pancreatic enzymes for diarrhea in these patients. GCRC monitoring is critical to accurately assess stool volume and fat content on both placebo and active drug.